The embodiments described herein relate generally to Computer-aided design (CAD) and, more particularly, to automatically aligning one or more secondary objects using an alignment tool.
Computer-aided design software allows a user to construct and manipulate complex three-dimensional (3D) models. A number of different modeling techniques can be used to create a 3D model. These techniques include, for example, solid modeling, wire-frame modeling, and surface modeling. Some known solid modeling techniques provide for topological 3D models, where the 3D model is a collection of interconnected topological entities such as vertices, edges, and faces. Moreover, some known topological entities have corresponding supporting geometrical entities such as points, trimmed curves, and trimmed surfaces. Trimmed surfaces correspond to the topological faces bounded by the edges. Some known wire-frame modeling techniques, on the other hand, can be used to represent a model as a collection of simple 3D lines, whereas surface modeling can be used to represent a model as a collection of exterior surfaces. CAD systems may combine these and other modeling techniques, such as parametric modeling techniques. Parametric modeling techniques can be used to define various parameters for different features and components of a model, and to define relationships between those features and components based on relationships between the various parameters.
A design engineer is one typical user of at least some known 3D CAD systems. A design engineer designs physical and aesthetic aspects of 3D models, and is skilled in 3D modeling techniques. The design engineer creates parts and may assemble the parts into a subassembly. A subassembly may also consist of other subassemblies. An assembly is designed using parts and subassemblies.
At least some known CAD systems may also support two-dimensional (2D) objects, which are 2D representations of 3D objects. Two-dimensional and three-dimensional objects are useful during different stages of a design process. Three-dimensional representations of a model are commonly used to visualize a model in a physical context because the designer can manipulate the model in 3D space and can visualize the model from any conceivable viewpoint. Two-dimensional representations of a model are commonly used to prepare and formally document the design of a model. A 2D representation of the 3D model is referred to as a 2D drawing, or simply, a drawing. A 2D drawing contains one or more drawing views where each view illustrates the model in a specific orientation (e.g., top, front, or left view), or illustrates a detail or section view of the model. In general, the 2D drawing is used to communicate the design to a manufacturing engineer so that the physical object corresponding to the 2D drawing, and therefore, also corresponding to the 3D model, can be built.
Formally documenting a design includes annotating a CAD model using a set of geometric dimensioning formulations thereby enabling a design engineer to communicate the configuration of a part, a subassembly, or an assembly to a manufacturing engineer. The International Standards Organization (ISO) and the American Society of Mechanical Engineers (ASME), among others, establish design and manufacturing standards, which are uniform practices for stating and interpreting dimensioning data. However, annotating a 3D model or a 2D drawing that represents a 3D model in a manner that is clear, concise, and compliant to ASME, ISO, or other dimensioning and tolerancing standards can be an arduous task. Such annotating of 2D drawings may be one of the most tedious and time consuming CAD requirements, which becomes more complicated the more complex the CAD design.
Using at least some known CAD systems, a design engineer may create dimension annotations using a freeform technique. For example, the design engineer can place dimension annotations anywhere within the drawing by moving (e.g., dragging) the dimension indicia (e.g., dimension annotation text or leader line) using a cursor-controlled I/O device, such as a mouse. However, the design engineer should comply with a defined standard. The defined standard governs the offset distances of the dimension lines, on which side of an edge the dimension annotation should be placed, and the angle of a leader (if applicable). Typically in a 2D drawing that complies to a predefined standard, when a dimension is being added to a model, there are predetermined limited logical locations the dimension indicia can be placed. Moreover, design engineers need to select a location where leader lines and text do not overlap. Although sometimes leader lines do need to overlap for lack of space, the text should never overlap. Furthermore, the design engineer often has to manually lineup dimension indicia of one dimension annotation with dimension indicia of other dimension annotations to create a legible and aesthetically pleasing drawing. As more dimensions are added, the area available to place subsequent dimension annotations is reduced, especially since the dimensions already placed are fixed until the design engineer manually changes them.
Similarly, design engineers may need to include secondary images for use in better exhibiting properties of the design. For example, a design engineer may include one or more 2D drawings that illustrate different viewing angles of a 3D model. The design engineer needs to select a location where the 2D drawings and the 3D model do not overlap to avoid obscuring properties and/or features of the 3D model. Furthermore, the design engineer often has to manually lineup the 2D drawings to create a legible and aesthetically pleasing presentation. As more 2D drawings, annotations, and the like are added, the area available to place subsequent drawings and/or annotations is reduced.
Accordingly, a need exists for a design engineer to apply secondary objects, such as 2D drawings, annotations, and the like within a presentation of a 3D model without requiring the time-consuming manual entry and organization methods described above.